Understanding the Area of a Circle

What is the diameter of a circle?

• The distance across the circle through the center

• The distance from the center to the edge of the circle

• The circumference of the circle

• The area inside the circle

Which of the following is the formula for the area of a circle?

• pi * diameter squared

• pi * radius squared

• pi * radius

• pi * diameter

What is the approximate value of pi used in calculations?

• 3.13

• 3.14

• 3.16

• 3.15

If the radius of a circle is 3.9 cm, what is the approximate area?

• 47.76 square cm

• 48.76 square cm

• 49.76 square cm

• 46.76 square cm

What is the first step when calculating the area of a circle given the diameter?

• Square the diameter

• Divide the diameter by two to find the radius

• Use the diameter directly in the formula

• Multiply the diameter by pi

If the diameter of a circle is 5 inches, what is the radius?

• 1.5 inches

• 2.5 inches

• 5 inches

• 10 inches

What is the area of a circle with a diameter of 12 meters?

• 113.04 square centimeters

• 113.04 square meters

• 113.04 square feet

• 113.04 square inches

Why is it important to convert diameter to radius when calculating the area?

• Because diameter is not used in any formula

• Because diameter is always larger

• Because the formula uses radius, not diameter

• Because radius is easier to measure

If the radius of a circle is doubled, how does the area change?

• The area is doubled

• The area is halved

• The area is quadrupled

• The area remains the same

What should you be careful about when reading a problem involving circle area?

• Ensure you use the diameter in the formula

• Ensure you use the radius in the formula

• Ensure you use the circumference in the formula

• Ensure you use the area in the formula